Abstract

Forming technology of protective properties using concentrated energy flows is based on the possibility of laser radiation firstly to provide high heat flow densities which are necessary for intensive heating on a small part of surface. When effecting metal surface laser radiation reflects from it partially and the rest flow penetrates on small depth. As far as the energy is practically absorbed fully in the surface layer, width 10-6 to 10-7 m, the heat source may be considered as surface one [1]. To harden steel products it is necessary to heat the surface till the temperature of phase transformations. The surface cooling takes place mainly due to heat transfer to a less heated member part. Mathematical modeling thermal processes occuring when local surface parts processing is one of effective means to study this method of materials hardering. However till now the predominant number of works of temperature fields investigation when local processing was done supposing that the ray effects semi-infinite space or the process is considered in a moving coordinates system, connected with the centre of a light spot, that enables to consider a stationary task. Such assumption are true when processing massive parts but give a considerable error when processing small parts [2]. The offered models with the aid of which there is studied the heating process for a sample of parallepiped and cylinder shape come to solving the equation of thermal conductivity with considerably nonlinear coefficients. When surface processing with continuity laser, the ray is focused perpendicularly to the sample surface. The period of light spot contact with the surface is estimated from the speed of its travel on the scanned surface. Before the test the product is subjected to special processing reducing the energy loss due to reflection.

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